CN-122026715-A - Power converter

CN122026715ACN 122026715 ACN122026715 ACN 122026715ACN-122026715-A

Abstract

A power converter (11) is provided with a plurality of branches (4), each branch (4) having a series circuit of a high-potential side main switch (S1) and a low-potential side main switch (S2), resonance capacitors (C1, C2) connected in parallel with the main switches (S1, S2), and a series circuit of two auxiliary switches (A1, A2) and a resonance inductor (L), wherein one end of the series circuit of each branch (4) is connected to a common connection point of the main switches (S1, S2) and the other end is connected together. A control unit (13) controls each branch (4) so as to perform soft switching, and corrects the timing of switching the auxiliary switches (A1, A2) so that the on-time ratio of the main switches (S1, S2) between the branches (4) becomes a desired value.

Inventors

MATSUNAGA HIDEYA

Assignees

株式会社电装
丰田自动车株式会社
未来瞻科技株式会社

Dates

Publication Date: 20260512
Application Date: 20251103
Priority Date: 20241111

Claims (5)

1. An electric power converter, comprising: A power conversion unit including a plurality of branches each having a series circuit of a high-side main switch and a low-side main switch, a series circuit of a resonance capacitor and two auxiliary switches and a resonance inductor, each connected in parallel to the high-side main switch and the low-side main switch, one end of the series circuit of each branch being connected to a common connection point of the high-side main switch and the low-side main switch and the other end being connected together, the two auxiliary switches being two transistors sharing a drain or an emitter and constituting a bidirectional switch, and A control unit that controls the switches of the switches constituting the power conversion unit; The control unit controls each of the branches so as to perform soft switching, and corrects the timing of switching the main switch or the auxiliary switch so that the on-time ratio of the main switch between the branches becomes a desired on-time ratio.
2. The power converter of claim 1, wherein the power converter comprises a power converter, The control unit is provided with: An ideal on-timing calculation unit that calculates an on-time and an ideal on-timing of the main switch for obtaining a target output from the power conversion unit; a main switch control unit that performs switching control of the main switch according to the on-time and the ideal on-timing; An auxiliary switch on timing correction unit for correcting a preset on timing of the auxiliary switch, and An auxiliary switch control unit that performs switching control of the auxiliary switch according to the corrected on timing; the auxiliary switch on timing correction unit calculates an on timing delay time of the main switch corresponding to a switching operation of the auxiliary switch, and corrects an on timing of the auxiliary switch based on the on timing delay time.
3. A power converter according to claim 2, wherein, The control unit includes an on-timing detection unit that detects an actual on-timing of the main switch in the power conversion unit, The auxiliary switch on timing correction unit additionally corrects the on timing of the auxiliary switch so that the actual on timing coincides with the ideal on timing.
4. The power converter of claim 1, wherein the power converter comprises a power converter, When one of the plurality of branches is set as a master branch and the other of the plurality of branches is set as a slave branch, The control unit is provided with: An ideal on-timing calculation unit that calculates an on-time and an ideal on-timing of the main switch in each branch for obtaining a target output from the power conversion unit; a main switch control unit for performing a switch control of the main switch according to the on-time and the ideal on-timing, and An auxiliary switch on timing correction unit for correcting a preset on timing of the auxiliary switch in the slave branch based on the ideal on timing, and An auxiliary switch control unit that performs switching control of the auxiliary switch of the slave branch according to the corrected on timing; the auxiliary switch on timing correction section calculates a difference between an ideal on timing in the master leg and an ideal on timing in the slave leg, and corrects the on timing of the auxiliary switch in the slave leg based on the difference.
5. The power converter of claim 1, wherein the power converter comprises a power converter, The control unit is provided with: An ideal on-timing calculation unit that calculates an on-time and an ideal on-timing of the main switch for obtaining a target output from the power conversion unit; a main switch control unit that performs switching control of the main switch according to the on-time and the ideal on-timing; an auxiliary switch control unit for performing switch control of the auxiliary switch, and And a main switch off timing correction unit that calculates an on timing delay time of the main switch corresponding to a switching operation of the auxiliary switch, and corrects an off timing of the main switch based on the on timing delay time.

Description

Power converter Technical Field The present invention relates to a power converter that performs switching control of an ARCP (Auxiliary Resonant Commutated Pole: auxiliary resonant converter pole) system. Background For example, in patent document 1, a DC/DC conversion circuit including an ARCP circuit includes a control unit 11A for controlling main switches S1 and S2 and resonance switches S3 and S4, and a storage unit 12A storing a1 st calculation formula related to operation timing for turning on the main switches S1 and S2. The control unit 11A performs a switching process of calculating a1 st time from when the resonance switches S3 and S4 are turned on to when the main switches S1 and S2 are turned on based on the 1 st calculation formula and turning on the main switches S1 and S2 at the end of the 1 st time, and performs control of correcting and updating the 1 st calculation formula so as to reduce the amount of deviation between the crossing timing and the operation timing at which the fall of the resonance current IL2 crosses the reactor current IL 1. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 2023-096959 Disclosure of Invention Specifically, in patent document 1, control is performed such that the main switch is turned on after a1 st time T1 has elapsed since the resonance switch was turned on. The 1 st time T1 increases and decreases in proportion to the output current amount I load according to the 1 st calculation formula. In the DC/DC conversion circuit as in patent document 1, since the number of branches of the main switch is one, delay at time T1 does not become a problem. However, in an inverter circuit having a three-phase structure, for example, on timings of main switches in each branch may be unevenly shifted, which causes a problem in output control. That is, in the three-phase ac, since the output line voltage is determined by the ratio of the relative on-duty of the UVW phase pulses, the duty varies when the resonance waiting time of each phase varies. This causes a difference in the voltages between the three phases or a decrease in the maximum output. The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a power converter that can control an output voltage to be a desired level in a configuration including a plurality of branches and auxiliary switches corresponding to the respective branches. According to claim 1 of the present disclosure, in the power converter, the power conversion unit includes a plurality of branches, each of which has a series circuit of a high-potential side main switch and a low-potential side main switch, a resonance capacitor connected in parallel with each main switch, and a series circuit of two auxiliary switches and a resonance inductor that constitute a bidirectional switch, one end of the series circuit of each branch being connected to a common connection point of the two main switches, and the other end being connected together. The control unit controls each of the branches so as to perform soft switching, and corrects the timing of switching the main switch or the auxiliary switch so that the on-time ratio of the main switch between the branches becomes a desired on-time ratio. With this configuration, even when it is assumed that the timing at which the main switch of each branch is turned on is delayed from the desired timing in association with the switching operation of the auxiliary switch, the control unit corrects the on-time ratio of the main switch between the branches to be the desired one. This makes it possible to control the difference between the voltages output from the respective branches of the power conversion unit to be a target value. According to claim 2 of the present disclosure, the ideal on-timing calculation unit of the control unit calculates the on-time and ideal on-timing of the main switch for obtaining the target output from the power conversion unit. The main switch control unit performs the switch control of the main switch based on the on time and the ideal on timing. The auxiliary switch on timing correction unit corrects a preset on timing of the auxiliary switch, and the auxiliary switch control unit performs switching control of the auxiliary switch based on the corrected on timing. Specifically, the auxiliary switch on timing correction unit calculates an on timing delay time of the main switch corresponding to the switching operation of the auxiliary switch, and corrects the on timing of the auxiliary switch based on the on timing delay time. By correcting in this way, the timing at which the main switch is turned on can be advanced by the amount of the delay time to coincide with the ideal on timing. According to the 3 rd aspect of the present disclosure, the on-timing detecting section of the control section detects the actual on-timing of the main switch in the power converting section. The aux